Cloud computing is the use of computing resources (hardware and software) delivered as a service over a network, such as the Internet. In a business model using software as a service, users are provided access to application software and databases via cloud computing. The service providers manage the infrastructure and platforms on which the applications run. In addition to software as a service, other cloud based services commonly are available to users, for example social networking services, banking services, e-mail services, instant messaging services, data storage services, etc. Typically these services require a user name and password to be authenticated before a user can use the services.